The alien of legal status in this country can easily produce the necessary evidence in four different ways: First. showing his declaration of intention to become a citizen. The minute he takes out his first papers he must show legal entry. The mere possession of his declaration of intention is proof positive that he is here legally. second. he can produce an identification card which has been issued to all aliens since July 1. 1928. and which was given him when he applied for a visa in his native country. third. he can produce a letter from the Department of Labor. through the port of entry where he arrived. and he can obtain this letter without it costing him a cent. fourth. he can produce a certificate of registry. if he has been registered under the act of March 2. 1929. Every alien here legally has at least three of these documents with him. and he can obtain any one of them without any expense whatsoever. The amendment has been worded so that it is negative limitation.